Reaction time and onset of psychological distress:The UK Health and Lifestyle Survey

BACKGROUND: Cross-sectional studies have shown that depression is often accompanied by less efficient cognitive function, as indicated by slower speed of information processing. The direction of effect is unclear. We investigated prospectively whether slower processing speed, as indexed by longer simple or choice reaction time, is associated with an increased risk of psychological distress. METHODS: Participants were 3088 men and women aged 18 and over who had taken part in the UK Health and Lifestyle Survey. Simple and choice reaction time was measured in the baseline survey. Symptoms of psychological distress were assessed at baseline and at the 7-year follow-up survey with the 30-item General Health Questionnaire (GHQ). RESULTS: In unadjusted models, a SD slower simple or choice reaction time at baseline was associated with ORs for psychological distress (≥5 on GHQ) at follow-up of 1.14 (1.06 to 1.23; p<0.001) or 1.13 (1.04 to 1.22; p=0.002), respectively. Further adjustment for age, sex, social class, educational attainment, health behaviours, number of chronic physical illnesses present, neuroticism and GHQ score at baseline had only slight attenuating effects on these associations. In fully adjusted models, a SD slower simple or choice reaction time at baseline was associated with ORs for psychological distress of 1.11 (1.02 to 1.21; p=0.017) or 1.11 (1.00 to 1.24; p=0.048), respectively. CONCLUSIONS: Slower processing speed may be a risk factor for the development of psychological distress. Future studies should explore the extent to which slower processing speed explains previously demonstrated associations between lower intelligence and poorer mental health

Altitude and latitude variations in trait-impulsivity, depression, anxiety, suicidal risk, and negative alcohol-related consequences in Argentinean adolescents

The aims of this research were threefold: 1) to analyze mental health state both general (GMHS, i.e., self-perceived health and psychological distress) and specific (SMHS; i.e., depression, trait-anxiety, negative alcohol-related consequences, and suicidal risk), and impulsivity-related traits (i.e., negative urgency, positive urgency, [lack of] perseverance, [lack of] premeditation, and sensation seeking) in a sample of Argentinean adolescent college students, in function of sex (women, men) and three different altitude-latitude regions (high-north, middle-center, low-south), for identifying common and specific features; 2) to analyze relationships between impulsivity-related traits and indicators of GMHS and SMHS, in the entire sample and in each altitude-latitude region, for understanding the importance of impulsivity-related traits in these forms of mental disorders; and 3) to analyze bivariate relationships between depression, trait-anxiety, negative alcohol-related consequences, and suicidal risk, in the entire sample and considering the three altitude-latitude regions, for testing two-disorder comorbidities. Scores on impulsivity-related traits differed by sex and by altitude-latitude region. GMHS and SMHS differed by sex but not by altitude-latitude region. Several relationships were found between impulsivity-related traits, GMHS, and SMHS as well as between indicators of SMHS. Some of these relationships were dependent on altitude-latitude regions, and implications of these findings were discussed.Fil: López Steinmetz, Lorena Cecilia. Universidad Nacional de Córdoba. Instituto de Investigaciones Psicológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Psicológicas; Argentina. Universidad Empresarial Siglo XXI; ArgentinaFil: Godoy, Juan Carlos. Universidad Nacional de Córdoba. Instituto de Investigaciones Psicológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Psicológicas; ArgentinaFil: Fong, Shao Bing. University of Melbourne; Australi

Individual behavioral phenotypes: An integrative meta-theoretical framework. Why “behavioral syndromes” are not analogs of “personality”

Animal researchers are increasingly interested in individual differences in behavior. Their interpretation as meaningful differences in behavioral strategies stable over time and across contexts, adaptive, heritable, and acted upon by natural selection has triggered new theoretical developments. However, the analytical approaches used to explore behavioral data still address population-level phenomena, and statistical methods suitable to analyze individual behavior are rarely applied. I discuss fundamental investigative principles and analytical approaches to explore whether, in what ways, and under which conditions individual behavioral differences are actually meaningful. I elaborate the meta-theoretical ideas underlying common theoretical concepts and integrate them into an overarching meta-theoretical and methodological framework. This unravels commonalities and differences, and shows that assumptions of analogy to concepts of human personality are not always warranted and that some theoretical developments may be based on methodological artifacts. Yet, my results also highlight possible directions for new theoretical developments in animal behavior research

Reaction time in adolescence, cumulative allostatic load, and symptoms of anxiety and depression in adulthood:The west of Scotland twenty-07 study

Objective: to examine the relation between reaction time in adolescence and subsequent symptoms of anxiety and depression and investigate the mediating role of sociodemographic measures, health behaviors, and allostatic load.Methods: participants were 705 members of the West of Scotland Twenty-07 Study. Choice reaction time was measured at age 16. At age 36 years, anxiety and depression were assessed with the 12-item General Health Questionnaire (GHQ) and the Hospital Anxiety and Depression Scale (HADS), and measurements were made of blood pressure, pulse rate, waist-to-hip ratio, and total and high-density lipoprotein cholesterol, C-reactive protein, albumin, and glycosolated hemoglobin from which allostatic load was calculated.Results: in unadjusted models, longer choice reaction time at age 16 years was positively associated with symptoms of anxiety and depression at age 36 years: for a standard deviation increment in choice reaction time, regression coefficients (95% confidence intervals) for logged GHQ score, and square-root–transformed HADS anxiety and depression scores were 0.048 (0.016–0.080), 0.064 (0.009–0.118), and 0.097 (0.032–0.163) respectively. Adjustment for sex, parental social class, GHQ score at age 16 years, health behaviors at age 36 years and allostatic load had little attenuating effect on the association between reaction time and GHQ score, but weakened those between reaction time and the HADS subscales. Part of the effect of reaction time on depression was mediated through allostatic load; this mediating role was of borderline significance after adjustment.Conclusions: adolescents with slower processing speed may be at increased risk for anxiety and depression. Cumulative allostatic load may partially mediate the relation between processing speed and depressio

Peripheral blood and neuropsychological markers for the onset of action of antidepressant drugs in patients with Major Depressive Disorder

<p>Abstract</p> <p>Background</p> <p>In Major Depressive Disorder (MDD), treatment outcomes with currently available strategies are often disappointing. Therefore, it is sensible to develop new strategies to increase remission rates in acutely depressed patients. Many studies reported that true drug response can be observed within 14 days (early improvement) of antidepressant treatment. The identical time course of symptom amelioration after early improvement in patients treated with antidepressants of all classes or with placebo strongly suggests a common biological mechanism, which is not specific for a particular antidepressant medication. However, the biology underlying early improvement and final treatment response is not understood and there is no established biological marker as yet, which can predict treatment response for the individual patient before initiation or during the course of antidepressant treatment. Peripheral blood markers and executive functions are particularly promising candidates as markers for the onset of action and thus the prediction of final treatment outcome in MDD.</p> <p>Methods/Design</p> <p>The present paper presents the rationales, objectives and methods of a multi-centre study applying close-meshed repetitive measurements of peripheral blood and neuropsychological parameters in patients with MDD and healthy controls during a study period of eight weeks for the identification of biomarkers for the onset of antidepressants' action in patients with MDD. Peripheral blood parameters and depression severity are assessed in weekly intervals from baseline to week 8, executive performance in bi-weekly intervals. Patients are participating in a randomized controlled multi-level clinical trial, healthy controls are matched according to mean age, sex and general intelligence.</p> <p>Discussion</p> <p>This investigation will help to identify a biomarker or a set of biomarkers with decision-making quality in the treatment of MDD in order to increase the currently disappointing remission rates of antidepressant treatment.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00974155">NCT00974155</a></p

Performance test correlates of impulsivity and its component factors

A lack of consensus about the definition of impulsivity has led to difficulty in its measurement. This is a key issue in research on suicide, where impulsiveness appears to play an important role in suicidal risk. Impulsivity self-report scales exhibit low intercorrelations, are subject to response biases, and multiple subfactors have been identified on most instruments. Performance tests may be both less sensitive to response biases and more precise measures of the underlying dimensions of impulsivity. The current study evaluated relationships between three different performance measures of impulsivity (Time Production, Stop Signal Reaction Time Test, and Complex Reaction Time Test) and standard self-report scales in 40 non-patient subjects. The three performance tests were compared to a composite aggression/impulsivity index derived from three separate self-report scales (Barratt Impulsiveness Scale or BIS, Buss-Durkee Hostility Inventory, and Brown-Goodwin Aggression History), and to a well validated impulsiveness scale containing both general and subfactor scores of impulsive behavior (BIS). It was hypothesized that each performance test assessed a unique aspect of impulsivity, and that a combination of these tests would provide a better estimate of general impulsivity than any one score alone. The performance measures were not significantly correlated with one another. In combination, they did not significantly predict the composite aggression/impulsivity score, but were significantly associated with the total score on the specific impulsiveness measure (BIS). In turn, each performance test was most strongly correlated with the subfactor score on the BIS representing the dimension that it was hypothesized to measure: Time Production with Cognitive Impulsiveness, Stop Signal with Motor Impulsiveness, and Complex RT with Nonplanning Impulsiveness. The power of this study was limited, given the observed effect sizes, and there were few highly impulsive subjects, but the pattern of results was similar to that predicted. These findings support the notion that impulsiveness is a multidimensional construct, and that multiple measures, including both performance tests and well-validated self-reports, provide the most effective means of assessing impulsivity in a comprehensive and clinically useful fashion

Questionable Dementia: Clinical Course and Predictors of Outcome

OBJECTIVE:To evaluate the clinical course and predictors of outcome in outpatients with cognitive impairment who do not meet criteria for dementia at initial evaluation. DESIGN: Naturalistic longitudinal study. METHODS: Cognitively impaired patients in a memory disorders clinic who fell between the “normal” and “dementia” categories were defined broadly as “questionable dementia” (QD).Of 127consecutiveQ D patients, 75were followed for a minimum of 1year (mean 2.5 years, SD 1.7).Baseline neuropsychological testing was conducted in 62 of these 75 QD patients. RESULTS:: At the final follow-up time-point, 41.3% met diagnostic criteria for dementia (27 of 31 patients with dementia had possible or probable Alzheimer’s Disease, AD), 44% were rated as not demented, and 14.7% remained as “uncertain” dementia. Increased age was associated with the final diagnosis of dementia, but duration of follow-up, Clinical Dementia Rating, and modified Mini Mental State (mMMS) scores were not predictive. Low scores on the mMMS delayed recall subtest, consistent long-term retrieval on the Selective Reminding Test, category naming for animals, and the WAIS-R digit symbol, picture arrangement, and block design subtests were predictive of the final diagnosis of dementia (all P 5.01). mMMS delayed recall showed 66.7% sensitivity and 71.4% specificity, the other five neuropsychological subtests together showed 66.7% sensitivity and 66.7% specificity, and the six tests together showed 81% sensitivity and 76.9% specificity. Similar predictive accuracy was obtained for the final diagnosis of AD. CONCLUSIONS:In Q D patients, poor performance on the mMMS delayed recall item may be a useful predictor of the diagnosis of dementia (and AD) on follow-up. Combining a screening instrument like the mMMS with specific neuropsy

Cerebral blood flow patterns underlying the differential impairment in category vs letter fluency in Alzheimer's disease

Verbal ¯uency tasks are used to assess language functioning in Alzheimer's disease (AD), and performance typically declines as the disease progresses. However, several studies have shown that Category Fluency performance (produce words from a category) declines faster than Letter Fluency performance (produce words beginning with a certain letter), which is not the case for other dementias. The purpose of this study was to determine if each of these two types of ¯uency tasks was associated with di€erent patterns of cerebral blood ¯ow abnormality in AD. A resting, Xenon-inhalation regional cerebral blood ¯ow measurement (133Xe rCBF) and neuropsychological evaluation was administered to 25 patients with probable AD and 24 healthy elderly controls. Stepwise regression using rCBF measures as predictor variables was used to predict Category and Letter Fluency performance, in both a combined group of patients and controls, and in the patient group alone. Correlations were also computed between rCBF variables and the di€erence between normatively corrected scores on each task for each subject, which characterized the extent of the discrepancy between them. In full sample regressions, both Category and Letter Fluency were predicted by education and the decline in left inferior parietal ¯ow, a focal AD-related de®cit. Additional variance in Category ¯uency, however, was predicted by global mean ¯ow, while additional variance in Letter Fluency was predicted by frontal ¯ow. Within the patient sample, in turn, the primary predictor of Category Fluency was mean ¯ow; the primary predictor of Letter Fluency was left-sided frontal ¯ow. Analysis of the ¯uency di€erence score revealed that relatively greater impairment of Category Fluency was associated with more typical, AD-related de®cits in posterior temporal and parietal perfusion. When the two were equivalently impaired, typical AD-related de®cits were accompanied by marked de®cits in frontal perfusion. These ®ndings are consistent with the underlying neuropsychology of these tasks, and suggest that Category Fluency's stronger association to the most typical CBF de®cits of AD account for its greater sensitivity to this disease. Letter Fluency de®cits, on the other hand, carry signi®cant information about the degree to which perfusion de®cits have spread to frontal cortex. # 1999 Elsevier Science Ltd. All rights reserved